🚀 go-pugleaf

In article <1992Nov17.002150.60825@ns1.cc.lehigh.edu> twb0@ns1.cc.lehigh.edu (Thomas Brown) writes:
>An article was posted recently stating that there was an upgrade which
>could be performed on the Zenith 386/16 1-meg 32-bit memory card which
>would allow it to take 1MB DRAM (to upgrade the board to 4-megs).
>
>I would appreciate any information on this upgrade; feel free to post
>to the net so that others can view it as well.
>
>Thanks much,
>-Tom

OK - here is the info you guys asked for.  To upgrade the Zenith 1 Meg card
to a 4 Meg card do the following steps:

		1) remove all the 256k memory chips
		2) remove the memory chip sockets VERY CAREFULLY.
		3) remove the solder from the holes for the 18 pin
                   sockets ( the 18 pin holes are offset to the left )
		4) install the 18 pin sockets
		5) change U464 from a 444-558 to a 444-529
		6) change U470 from a 444-559 (or a 444-670) to a 444-530
		7) move R405 to R404
		8) move R406 to R407
		9) remove R410
		10) 33 ohm resistors should be added at R14, R15, and R16
		11) install the 1 Meg DIP chips

Suffice it to say this modification is not for the light at heart.  Removing
36 16-pin sockets and clearing the holes for 36 18 pin sockets should only
be attempted by someone who is very familiar with proper soldering techniques.
The 444-529 and the 444-530 can be purchased from ZDS and I assume any ZDS
dealer.  You might even be able to get them from Heath.

Good Luck!
--
    Kent Phelps         |         Internet:   kent@eng.ufl.edu
Digital Design Facility |         Phone:      904-392-2464
"We will vote for a gerbil if necessary to get rid of George Bush and Dan Quayle
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